Webster’s Revised Unabridged Dictionary · 1913
Relapse
Re·lapse′ (r?-l?ps′), v. i. [imp. & p. p. Relapsed (-l?pst′); p. pr. & vb. n. Relapsing.] [L. relapsus, p. p. of relabi to slip back, to relapse; pref. re- re- + labi to fall, slip, slide. See Lapse.] 1. To slip or slide back, in a literal sense; to turn back. [Obs.] Dryden.
2. To slide or turn back into a former state or practice; to fall back from some condition attained; — generally in a bad sense, as from a state of convalescence or amended condition; as, to relapse into a stupor, into vice, or into barbarism; — sometimes in a good sense; as, to relapse into slumber after being disturbed.
That task performed, [preachers] relapse into themselves. Cowper.
3. (Theol.) To fall from Christian faith into paganism, heresy, or unbelief; to backslide.
They enter into the justified state, and so continue all along, unless they relapse. Waterland.
Re·lapse′, n. [For sense 2 cf. F. relaps. See Relapse, v.] 1. A sliding or falling back, especially into a former bad state, either of body or morals; backsliding; the state of having fallen back.
Alas! from what high hope to what relapse Unlooked for are we fallen! Milton.
2. One who has relapsed, or fallen back, into error; a backslider; specifically, one who, after recanting error, returns to it again. [Obs.]